LiFePO4 Batteries: Discussion Thread for Those Using Them as House Banks

[john61ct]

Originally Posted by Maine Sail

A parallel block of individual 3.2V cells is one 3.2V cell as far as a BMS is concerned...

So additional per-cell gizmos within the parallel block? or just take your chances?

[HEN-BEL]

Lithium-ion creator helped develop a better battery technology

At 94 years old, John B. Goodenough isn't done changing the landscape of battery technology. The University of Texas at Austin professor who's widely credited for the invention of lithium-ion batteries has developed a better alternative. Goodenough, Cockrell School senior research fellow Maria Helena Braga and their team have created a low-cost solid state battery that's safer than lithium-ion. It stores thrice as much energy, which means more miles for electric vehicles in between charges. When you do need to charge, it can be done minutes instead of hours. Plus, it can withstand a greater number of charge and discharge cycles.

The team's technology uses glass electrolytes instead of liquid like lithium-ion does. By using solid glass, the new battery won't form dendrites -- whisker-like pieces of lithium that usually form in liquid electrolytes. They're the reason lithium-ion batteries have the tendency to short circuit and explode or start a fire.

The glass electrolytes also make it possible for the battery to operate in subzero degree (up to around -20 degrees Celsius or -4 degrees Fahrenheit) weather. And since their use means the creators replaced lithium with low-cost sodium, the batteries can be manufactured with earth-friendly materials. Someday, the new technology could make EVs more common and change the way we use our gadgets. For now, Goodenough and his team are looking to pair up with battery makers who can test their creation in electric vehicles and energy storage devices.

Source: University of Texas at Austin


More about John B. Goodenough HERE ----> https://en.wikipedia.org/wiki/John_B._Goodenough

[HEN-BEL]

Just read in the news:

Lithium-ion creator helped develop a better battery technology

At 94 years old, John B. Goodenough isn't done changing the landscape of battery technology. The University of Texas at Austin professor who's widely credited for the invention of lithium-ion batteries has developed a better alternative. Goodenough, Cockrell School senior research fellow Maria Helena Braga and their team have created a low-cost solid state battery that's safer than lithium-ion. It stores thrice as much energy, which means more miles for electric vehicles in between charges. When you do need to charge, it can be done minutes instead of hours. Plus, it can withstand a greater number of charge and discharge cycles.

The team's technology uses glass electrolytes instead of liquid like lithium-ion does. By using solid glass, the new battery won't form dendrites -- whisker-like pieces of lithium that usually form in liquid electrolytes. They're the reason lithium-ion batteries have the tendency to short circuit and explode or start a fire.

The glass electrolytes also make it possible for the battery to operate in subzero degree (up to around -20 degrees Celsius or -4 degrees Fahrenheit) weather. And since their use means the creators replaced lithium with low-cost sodium, the batteries can be manufactured with earth-friendly materials. Someday, the new technology could make EVs more common and change the way we use our gadgets. For now, Goodenough and his team are looking to pair up with battery makers who can test their creation in electric vehicles and energy storage devices.

Source: University of Texas at Austin

More about John B. Goodenough HERE ----> https://en.wikipedia.org/wiki/John_B._Goodenough


New technology at breakfast will be obsolete by dinner!

[transmitterdan]

Parallel cells appear as a single cell to the BMS.

[john61ct]

Yes I know, which is why I am asking about adding additional per-cell maybe-just-monitoring, on top of the "umbrella" protection offered by the REC unit.

I'm hoping this would be enough, more cost effective than going to the 16-cell REC, too $pendy for me, for now.

Then there are those say no LFP-specific BMS is even needed, as long as you're sure you keep to moderate current rates, lower range voltages and stay away from both top and bottom knees, moderate environmental temperatures, just good monitoring / logging systems only is safe enough?

[senormechanico]

You can't do that. Cells are connected with heavy, almost zero resistance connectors.
No electronics I can imagine will be able to separate what's going on in parallel connected cells, and I've been a professional electronics tech for over 30 years in the past.

[john61ct]

Sorry if I wasn't clear or maybe just my ignorance.

I thought there were per-cell units that worked independently of any centralized BMS "system".

I wasn't talking about having only wiring within the 4-cell "bottom level" parallel blocks, but having per-cell monitoring only at that level.

Then the "top-level" protective and balancing 4s BMS, would be hooked up as if to 4x 3.2 "block cells", without knowing about infra-issues within those lower-level blocks' 4 physical cells.

Maybe this is maybe just not a good idea, reasons?

Or just impossible, have to go to a full BMS designed for 4p4s or just do without completely, or. . . ?

[lev]

hello need some technical information... i have searched for a few hours and can not find an answer to what i need to understand. if have missed a post that deals directly with what i am asking please send link.

the story:

i have ordered 16 100ah cells from hpkbattery. i got an email that they are ready to ship and they all have a "inner resistance is around 12 mΩ" clearly this made me very concerned... so i asked them to verify this number. and please give me the actual numbers of there tests on the cells.

then i get back another email now saying "inner resistance is around 2 mΩ"

now clearly 'around' 2 mΩ has no meaning, and such an answer has me quite concerned... not only that, but it suggests that the cells they are sending are not even within there specified tolerance. and there printed specs on this are quite high to start with 'equal to or less then 2 mΩ'

questions.

what kind of resistance tolerance is expected for a well matched set of 100ah lifepo4 cells... +/- 0.1 mΩ? +/- 0.05 mΩ? ??? what is generally seen as an acceptable tolerance? what kind of tolerance spread is general seen from different manufacutres for match sets?

i want to make sure my thinking is correct before diving into this issue with
hpkbattery. some outside thoughts are welcome.

[john61ct]

Right to be "quite concerned", sounds to me like they're passing off QA rejects. Are they a lot cheaper than from more mainstream sources?

Direct from China seems super risky, are you going to pay the return shipping trying to get warranty replacements?

Or did sources you trust tell you they are a good outfit?

[lev]

at this moment i would like to just get some technical thoughts on my questions asked or personal information dealing directly with hpkbattery to keep things to the point... i will update with full results of what ends up happening with this order...

but i will say pricing of hpkbattery is quite high as far as general pricing of china cells go...

thanks.

[lev]

update

i just received an email from hpkbattery concerning the resistance of the cells they are shipping "I just checked our test record, 9 pcs are 1.2mΩ, 5 pcs are 1.1mΩ, 2pcs are 1.3mΩ."

i find a +/- 0.1mΩ to be acceptable...so i asked them to ship...

i should note... that up until the "around" resistance information that was set to me, dealing with hpkbattery has been very simple in all aspects... responses where quick, shipping arrangements simple.

i will let the forum know how they test when they arrive. the price is higher then most other cell manufactures but the cell quality is supposed to be very high... we will see.

[artesthuang]

This is Artest from HPKBATTERY (HANDPACK GROUP), any query for LiFePO4 battery, please contact hp@hpkbattery.com

[jram]

So, since I'm sitting here on the hook having disconnected 200Ah of my 400Ah (Gel) house bank after 8 years and many cycles I need to finally get serious about LFP.

Please see the attached.

The plan is to replace the 2P6S LA (Gel)s with 2P4S Calb 180Ah cells. Its a catamaran so I have 2 engines, a generator, Mass Combi Charger, Outback solar controller and a D400 regulated wind turbine as well. All of these can be tamed to sub-14V with the exception of the alternators that are the 'dumb' Volvo 115A units. I plan to tame them by having a separate contactor so they can be disconnected on longer motoring trips and/or automatically should I forget. I shall retain an 80Ah AGM battery on the no-loss charge splitters as a 'ballast' for the sake of the alternator regulators.

The type of BMS is still an open item and may vary between a programmable voltmeter and/or cell logger. I may even combine the cell logger with a home design controller to do the logic switching of contactors since I'd very much like to squirt the real-time battery info out to the internet so I can monitor if I'm off the boat.

I'm inviting comments and hints and tips although hoping to avoid religious wars.

[Hoopla]

Originally Posted by Maine Sail

Externally Rectified...

Yet another experiment. This time I am trying to get a cooler running alt and better performance by removing the rectification from the back of the alternator and moving it out of the engine bay.

In just one year charging the LiFePO4 bank the magnet wire coating is severely darkened due to pushing the alternator too hard. I don't have room for a large frame alternator so tweaking a small case alt is my best option.

The math seems to predict that I should be able to drive this alt at nearly full bore and not over heat it. I will report on performance once it is installed and up and running..

Originally Posted by Maine Sail

Just a quick update on my external rectification modification.

Since converting to external rectification, of my small case CS130D based alternator, I can continuously run about 20A more than I previously could and do so without over heating.. So far my peak recorded temp has been 218F on a charge from 80% DOD with a 1:20 minute run.. I am using a remote cylinder head temp monitor for motorcycles that captures peak temps and holds them in memory so I don't have to stare at it all the time......

So far this mod seems to be working well in my application but I still want to get more data. The conversion was done for my by Mark Grasser DC Solutions.

Still I think the best option is to go to a large frame alternator designed and intended for high output for long duration's. I did not have the room for this and already have a Sea Frost system so getting the most out of a small frame alt was in order...

Mainesail I'm doing exactly the same thing, on account I'm stuck with going small case on account of room plus I want to keep crankshaft/journal load down low and close as possible to horizontal and using two alternators to counter balance that load on the crank/journals.

I am assuming you have simply tapped into the AC stator leads to bring the 3 phases out and left the internal rectifier in place and have not linked the DC output of both the internal and external rectifier via their - and + posts? Therefore the internal rectifier is obviously doing nothing.

That said you might have also removed the existing internal bridge for better internal ventilation to the windings? I would like to retain mine for redundancy in case the external bridge goes down but haven't settled on that yet.

If your internal bridge is still in place and this is still on your bench an interesting experiment might be to compare the temperatures of both bridges DC output being linked and with the greater thermal efficiency of having more diodes versus no link, just relying on the external bridge, less diodes but no rectifying heat inside the alternator.

Also how long a cable run for the 3 phase out are you using as I assume the longer it is the greater the output DC current drops?

[lev]

i have a huge review of dealing with hpk batterys so far... i ordered 16 100ah cells from this company

lithium-ion battery,LiFePO4 battery,lithium battery,lithium iron phosphate battery,power battery Manufacturers & Suppliers - Shenzhen Handpack Technology Co., Ltd
Shenzhen Handpack Technology Co., Ltd
Address:
Building K, Linghangyuan, Industrial Park,Banxuegang 163, Longgang District, Shenzhen, Guangdong, China (518000)
Tel:
(86 755) 29574434
Fax:
(86 755) 28170756
Mobile:
(86) 18823411191

the contact i have been dealing with is huang jian wei aka artist.

i already made a post asking about some things having to do with these cells. and here it is... if you have already read it just skip it.

------------------------------------------------------
hello need some technical information... i have searched for a few hours and can not find an answer to what i need to understand. if have missed a post that deals directly with what i am asking please send link.

the story:

i have ordered 16 100ah cells from hpkbattery. i got an email that they are ready to ship and they all have a "inner resistance is around 12 mΩ" clearly this made me very concerned... so i asked them to verify this number. and please give me the actual numbers of there tests on the cells.

then i get back another email now saying "inner resistance is around 2 mΩ"

now clearly 'around' 2 mΩ has no meaning, and such an answer has me quite concerned... not only that, but it suggests that the cells they are sending are not even within there specified tolerance. and there printed specs on this are quite high to start with 'equal to or less then 2 mΩ'

questions.

what kind of resistance tolerance is expected for a well matched set of 100ah lifepo4 cells... +/- 0.1 mΩ? +/- 0.05 mΩ? ??? what is generally seen as an acceptable tolerance? what kind of tolerance spread is general seen from different manufactures for match sets?

i want to make sure my thinking is correct before diving into this issue with
hpkbattery. some outside thoughts are welcome.

---------------------------------------------------------------

this had me quite worried but by this point they already had my payment in there account so i played it cool, tried to get some answers and they where not so satisfying but i stayed generally quite about it... said thank you and please ship... it is hard to complain when the company has your money and the product in there hands thousands of km away.

then the real problems started.... and i am gong to keep it short but try to paint a little of the picture... (nightmare)

hpk battery (handpack) hired airpak to provide door to door shipping to me and that is what i payed for that is what is on the invoice... after many phone calls airpak finally told me i must pay tax, but being a yacht in transit i do not have to pay tax on the shipment.... i myself tried to explain this to them as well as the marina who know what they are talking about. (this is something dhl, fedex, and ups do with out even contacting you, the shipment just arrives) this information was not easy to get... because airpak does not return phone calls or emails even if they say they will call back in 5 min... it means they will never call back... and when you do call back be it 15min later or the next day they still do not have answers... to keep this part of the story short because it is long... i gave up on not paying tax because i found out i can get it back if i go to a local government office if airpak gives proof i payed it... but this did not help... once i accepted this the run around continued.... please keep in mind i am talking to hpk battery (artist) telling him what is happening and if he can help me.... he was not so happy about this... not happy about helping me... at first he seemed to try but this is when his real rudness started.... he started actually telling me that i was lying to him. he found many reasons in his head to tell me this... i never lied once to him... not once... zero in any email i ever sent from the first contact and i have them all. i was just telling him what was happening and telling him that he hired this forwarder and he should be helping me take care of this... then he starts telling me i am wasting his time, lying to him, making things up... this is getting very strange to put it softly. very strange.

so after over two weeks of fighting with airpak and hpk battery finally i was in the marina office again trying to talk to airpak... it was hard... after so many weeks the fellow is telling me he can not answer my questions (my questions are how much is the tax and how do i pay?) and he must call me back... the marina staff saw my clear stress and frustration... i had been dealing with hpk battery and airpak for so long and they where seeing it take its tole one me... hpk battery being rude and abusive towards me and airpak not answering any of my questions... one of the staff kindly took the phone from me told the man how long till he calls back and then told him no, i expect your call in half an hour... he never called back...the marina staff looked at me and told me they will take care of this! and i was not in a position to refuse there kind offer... the office staff are amazing in pangkor marina in lumut malaysia. i can not stress that to many times just amazing. and if it was not for there many days and endless phone calls i would clearly not have the cells now...

in the end i had to pay a bribe requested from a employee of airpak, deposit funds directly into his personal account to get my cells... (i think i should stress it was me who did this, not the marina) after almost 3 weeks, after paying the bribe i got my cells in less than 12 hours. i guess this is what it was all about... depositing bribe money directly into employees bank accounts of airpak. i did not want to do this but i new i was never going to be able to get this shipment and i could not take up any more time of the marina staff! and as i am going through this i am dealing with the abuse and unimaginable rudeness of hpk battery...(i will give a few quotes so you can get it) hpk battery did nothing to assist in me getting my cells from there forwarder... they just kept telling me to contact the forwarder... one of may attempts of contact via email that i got my first reply after countless attempts a person contacted me (first time anyone from airpak contacted me) and told me they can not help me i must contact the shipper... this was via email so i could send the email to hpkbattery.com and i did. they answered me, talk to the forwarder (airpak)...??? but like i said in the end i payed the bribe and it was done and i never would have to deal with hpkbattery or airpak again... or so i thought.

then it gets worse... with in 10 min of getting my 16 cells my voltmeter shows me that all the cells look good voltage wise except one... all the cells are very close to 3.29 but one is 3.24... O crap!

i think but can not be sure, hpk battery did send me a quickly balanced set... and one of those cells can not hold voltage... ****! it looks like one cell is defective... i still have to deal with artist of hpk battery it is not over yet... and i thought before i start adding currents and attempt to balance them i should contact them. 0.04 difference is no small thing at this voltage with lifepo4 if they where sent balanced when they left as i was told they did. if that was true this is a defective cell. i already know i will have to deal with artist telling me i am lying and making things up which is what he does almost every email as of late... i had to deal with that every day from artist as i deal with airpak-express!

and now the hostility towards me becomes worse from this artist from hpk battery (handpack). like before it was not bad enough...

to give you an idea of what i was dealing with with hpk battery here are a few emails... please keep in mind this is after weeks of trying to get my package with the help of the marina in the end and a little at the start. and i hope you believe that i am not as they describe... if necessary i can put up the entire email transcript someplace if such a request is made... (it is over 100 emails) the more you read the more scary and strange it becomes as this fellow artist becomes more and more strange and abusive towards me... but i must keep it short there are hundreds of emails... and clearly i can not put them all up here. i am just going to put up 3 from the few days. but there are many like this...
---------------

You're still making things up... All cells are good quality, but you just made things up, no photos, no vedio, no any proves, just send one and one email... If we sent a faulty cell, we will give you warranty.
-(no request was made for more information, i have already proposed testing parameters)-

I am really fed up with you, please call me directly, it will save both time...
I know your real thought, you just intend keep making trouble to me and my company, if this will make you happy, ok, I really "admire" you... But does it real make you happy? Happy should not build on others painful...
However, I think you was a good person and I believe you will become what you should be.
I really appreciate if you act like a good and decent person.
-(this is passed the point of mental illness)-

Thank you,


Regards
Artest

-(now the really strange thing about this email is that all i have been doing is to try to get my package from there forwarder! and asking for there help! he has taken the idea that i have been lying to him about everything... i can not explain it because it is not rational.... and this kind of talk has been going on for a long time)- -(on one side i would like to think it is some kind of communication error... but when i kindly tell him i can ask the marina, who did most of the work to get this shipment from his forwarder, and deeply knows what has been happening, he will not respond and just tells me i am making things up. he will not accept verifying if i am lying or not with a great reference who knows exactly what happened!)-(pangkor marina is a good size marina with a big dry dock not some back woods place)

---------------------------




We're really regret to receive your order, because of your hostility and unreasonable request. What a pity...
-(after telling him there is no way for me to get my order this is what i get)--(i think maybe my unreasonable requests have been wanting them to help me get the shipment form what they call there forwarder. but really it is hard to reason any of this)-

Handpack is a big manufacturer in China, but obviously, I already spent lots of energy and time in you very very small order, I will not let my colleague spent more time for this meaningless issue.
-(because of all the hostility and accusations i have requested dealing with another contact at hpkbattery, if everything i say is shot down as being not true... everything! how can i deal with this? how do i speak to a person who tells me everything i say i make up? again i must say i never told him anything that was not a fact, no joke)-(every word i say to him is actually happening or is a true fact)

We both know your real purpose: you find a cheaper supplier, so you want refund from us even though we already ship to you, so you make things up...
-(i have no idea what he is speaking of/// i told him that after over two weeks i still can not get my cells from airpak in any possible way and that a refund at this point is best)--(my purpose is to get my cells that i payed for, and if i can not get them i want my payment back, at this point i do not think i will ever get them, i am making no progress just getting an endless runaround from hpk battery and airpak)-

I will inform all Chinese supplier regarding what you did and publish all emails in these website so that all Chinese supplier will refuse sell cells to you, especially I will let winston and calb sales know what happened. -(why he has decided to contact winston and calb is unknown to me and i could care less. my plan was to go back to lead acid and just forget about lifepo4 cells)--(at this point my regret of not just going lead acid is just deepening)-(as well if you are reading artist and you do publish ALL OUR email please do not forget to put a link on this forum)

My forwarder also will put you in blacklist, they will refuse ship your goods next time if they found you're the consignee.
-(thank god i will not have to pay any more bribes! or wast 10's of hours to find out they want bribe money that is why i have not gotten my cells!)--(please, please black list me)


However, if you still would like to be a good person, I think I will forgive what you did. You still will be our friend and my guest if you come to China. -(i have no idea what this nonsense is about?)-
-(i guess i am being forgiven for having to fight for many weeks to get my cells, in the end having to pay a bribe and having the audacity to asking for some real help)-



I hope you will become a decent person.



Best regards
Artest

----------------------------------------------------


Oviously, you are still making thing up and try to threaten me and my company..
-(i told him that i will be doing a review about what is going on weeks ago. so he understands what he writes will be published, i do not like being sneaky i like open)-

I don't why you keep saying I am rudeness, how can you say that??? There is no any word you can judge I am rudeness...
If you keep making things up, I will stop talk with you and publish all emails in Chinese supplier forums and inform all Chinese supplier and forwarder...

-(great)-(and keep in mind i have already suggested to artist i can check if it is ok if he calls the marina to hear what happened from them (he already has there phone number from the shipment)- i worry about this because he is so rude and the marina has helped me so much i do not want to expose those good people to him... but i thought if he wants a reference to what happened so maybe he can stops telling me i am making things up and deal with the defective cells, i would talk to the marina and see if they are willing... i imagine they would be fine with it... they got as frustrated as me with this gong show)- -(but i am waiting to see if artist will even be willing to take one step and see if his accusations are correct or just in his mind)--(after asking him 3 times he is not interested in speaking with anyone but keeps telling me i make things up...) (he will not even answer me) (it is like i never said it) (wow)



It will be the last email send to you if you keep making things up...
-(this is what he is now saying after i told him one cell of the 16 has a voltage problem. i think he thinks he has got me now so he can be even more abusive)-(maybe he thinks i will think i must accept his abuse if i want to possibly get a replacement cell, but really i do not understand any of it, impossible to say anything definitive when assessing this fellow)



If you're a decent man, you should let me know your address and mobile phone, not hide in darkness like...
-(he has my address, pangkor marina. the address he shipped the cells to. as with many cruzers i do not have a phone and i told him that. but he can always call the marina which is the contact number on the shipment. the "hide in the darkness like..." is just strange to the point i have nothing to say, how can i even address that?)-



Regards
Artest



--------------------------------------------------



I always respect all of my customers, never have hostility to anyone! Also I always try my best to handle this issue.
It is you, say something really rediculous and make no sense.
Oviously, I replied your boring email one by one, but get nothing, even a "thank you". Do you think my time is not time? -(i have to stress i am giving him detailed emails about what is going on so maybe he can help me get the cells from his forwarder)-

I think you know nothing about international express, I request you contact my forwarder agent in Malyasia, or provide necessary paper for clearance customs or assist my forwarder agent finish clearance customs, but you DID nothing!

-( i have yet to be given the opportunity to supply any papers to anyone let alone been told what papers anyone may need)- (no one will tell me anything) (shortly after that i got an email address from airpak with the help of the marina and sent them all my paperwork (they never asked for it, i was still working on just getting the basic answers of how do i get this shipment.) (the marina told me what they would need in papers)( so i sent them and then got no reply or action or solution of any kind from anyone) i told artist i finally got an email address from airpak and sent the papers. he actually told me that they got them and gave me a new contact number and name, so i called him and he could not tell me anything and said he would call back and he did not... he could not even say anything about papers)

you insist your action, I have nothing to do.
We did not intend sell cells to you, because as a end-user who don't know how to handle international business, and it come true now.

-(but you did and you sure had no problem taking my money)


Again, if you still do nothing, I will not reply you again.

-(him saying me doing nothing as i have made countless calls and attempts at contact of his forwarder and doing my best to keep him up to date)-(how do i deal with this?) now he is threatening me he will not reply to me again when i am doing everything i can and informing him of what is happening)


Please learn how to understand and repect people, thank you so much.


Best regards
Artest
Shenzhen Handpack Technology Co., Ltd.


----------------------------------------------------

there is just to much... i really would need to write a book about what has happened... but i must stop... i am tired and i am sure some of my writing is not very clear... so now i am sitting on 15 cells that look ok for now and 1 cells that may very well be defective.. and before proceeding i told artist how i would like to balance the cells and i want from him in writing that he accepts my way of testing or make a suggestion... i do not want to give him some excuse to tell me i voided the warranty so i am being very very careful. but at this request he only tells me i make things up... he will not answer if it is ok or not. or make a suggestion of what a good idea will be... so now i am just stuck with cells in a box sitting on my floor hoping i can get something in writing approving how we are going to do this so every one is happy...

i will let everyone know what happens next in this strange reality! i know i am beating my head against a stone. and i am sorry if it is hard to understand... it is late and i am so tired with all of this... i should have done this in the morning!